we need a mixture of different food groups that all do different jobs and we need to do exercise asswell to keep us fit and healthy. Here are some of foods we need to keep us healthy and the jobs they do

Metabolic rate
Respiration is a chemical reaction that allows cells to release energy from food. The metabolic rate is the speed at which such chemical reactions take place in the body and varies because of several factors, including age, gender and inherited factors.
Metabolic rate is also affected by the:
proportion of muscle to fat in the body
amount of exercise and other physical activity.
The metabolic rate increases as we exercise and stays high for a while afterwards. People who exercise regularly are usually healthier than people who don't.

OTHER FACTORS
Other factors affect health too, including inherited factors. For example, the cholesterol level in the blood can affect health.